----- Original Message -----
Sent: Monday, January 16, 2006 12:58
AM
Subject: [FlyRotary] Re: shake, rattle
and hum
You
had made mention of the prop being set at a high pitch angle, and that you
were going to reduce the pitch thinking that was part of the prop oscillation
problem. Did you reset the pitch angle? If you did then apparently
that was not the problem.
Hi
Bob,
Yep, I changed the pitch from 15
degrees at the tip, to 10 degrees, and it made no
difference.
Why not reduce more, go all the way to nearly flat
pitch, from what I remember that prop is a little on the big side for the
Kolb, isn't it.
Even if it doesn't produce any thrust (flat pitch),
it works as a flywheel - At least you eleiminate ANY ( if there is...) stall
issues at the tips....
FWIW
You might give some thought to adding mass to the engine. This might be
a situation where you could be adding weight to the wrong end of the vibration
problem.
Adding mass would be like adding
a heavy flywheel, or the missing rotor, but I'm not sure I follow
how it could be adding weight to the "wrong end
of the vibration
problem."
And why don't you have that
brandnew, easy to work with, etc. ACES on the machine,
yet??
If I am not wrong you can measure
any and everything with it! Even ceiling fans! Mine is down to 0.02 IPS
:))
There is also a "spectrum"
feature on it, to give you any resonante
frequencies...
Vibrations are a bitch (on
aircraft at least......), you might guess to the source based on what you
"feel" - it might
turn out to be a different source alltogether - the spectrum will help you
chase the source. You also can set up to measure imbalance of the engine alone
- Check wether you have all your counterweights clocked
correctly...
What I say is: You HAVE a
vibration analysis tool - and an easy to use one! Try it! Props is just one
ofthe many uses!
I
like the weather station, for some reason I thought it would be warmer
in Florida :>)
Despite what many people believe,
not all of Florida is in Miami. It's a big state, and we hide the best
part in the panhandle. Shhhh, don't tell anyone
:-)
21:56
1/15/06
I see you're with Bellsouth too
:-)
Cheers,
Rusty
Thomas J.